masking with a gif image with 8 bit depth

Is it possible to use a gif image with 8 bit depth(0-255) as a mask image? again, is it possible to separate red ,green and blue channel of a 8 bit depth gif image?

Answer 1

[Image Analyst]

It's possible. How do you want to mask it? You can either have some value that splits the mask into foreground and background (that's most common) or you can multiply the mask image by the gray image (this is less common). What, exactly, do you want to do?

Case 1, 255 stays the same and less than 255 in the mask image causes other image to become 0, or something like that.

Case 2. 255 stays the same, 0 becomes 0, and in between is proportional, like 128 in the mask image causes the other image to be less by a factor of 128/255, and so on.

[Mahua Nandy(Pal)]

thanx a lot.